Dehumidifier displays E4 and shuts down; may occur after running for some time.

Safety: Unplug the unit. Do not attempt to open the sealed refrigeration system (compressor, coils, refrigerant lines); that requires certified service.

• Clean air filter: Remove the front filter and wash with mild soap and water. Let it dry completely before reinstalling.
• Inspect airflow: Ensure the unit is at least 12 inches away from walls or furniture on intake and exhaust sides. Remove any obstructions to airflow.
• Clean coils: Remove the front cover to access the evaporator (cold) coil and rear cover for the condenser (warm) coil. Use a soft brush or vacuum with a brush attachment to remove dust and lint. Do not bend fins.
• Check fan operation: With covers back on loosely, power the unit and verify the fan runs at normal speed. If the fan is slow or not running, see fan-related entries.
• Inspect defrost/coil sensor: Locate the coil sensor on the evaporator or condenser (depending on model). Ensure it is firmly attached and wiring is intact. A loose sensor can misread temperature and trigger E4.
• Reset and test: After cleaning and checking sensors, unplug for 5 minutes, then restart. If E4 persists quickly, there may be a refrigerant or compressor issue.
• When to call a technician: If coils are icing heavily, compressor is very hot, or E4 returns despite good airflow and sensors, contact a qualified HVAC/appliance technician to check refrigerant charge and system pressures.